Patent EA-004258-B1 (EA)
Title: Induction furnace for steelmaking
IPC: F27D11/06
Filed: 2001-06-20
Abstract: 1. An induction heated furnace comprising a shell lined with refractory material; the furnace having at least walls and a floor; with at least one induction heater located in the floor of the furnace; the induction heater communicating with the interior of the furnace through a throat; the throat length being at least a substantial part of the service length of the induction heater. 2. An induction heated furnace as claimed in claim 1, comprising a shell lined with refractory material; the furnace having at least walls and a floor; with at least one induction heater located in the floor of the furnace; the induction heater communicating with the interior of the furnace through a throat; the throat length being more than at least half of the service length of the induction heater. 3. A furnace as claimed in claim 1 or 2, in which the furnace is a channel type furnace, the furnace is used in the melting or smelting of metals, the furnace has at least one burden charge hole and least one tap hole, and the furnace has at least one gas burner therein. 4. A furnace as claimed in any one of claims 1 to 3 wherein the furnace is used for steelmaking; and the furnace has at least one charge hole for iron containing burden. 5. A furnace as claimed in any one of claims 1 to 3 wherein the furnace is used for steelmaking; and the furnace has at least one charge hole for iron containing burden and reducing material. 6. A furnace as claimed in any one of claims to 3 to 5 wherein the burden includes scrap metal, reducing material, and other raw materials. 7. A furnace as claimed in any one of claims 1 to 6 wherein the throat has at least one baffle located substantially above the centre of the induction heater, the baffle being built into side walls of the throat, and the baffle, in use, directing the flow of molten metal through the throat. 8. A furnace as claimed in claim 7 wherein a plurality of baffles is located in the throat, the baffles being spaced apart. 9. A furnace as claimed in claim 7 or 8 wherein each baffle is wedge shaped and the wedge is located in the throat with the apex of the wedge directed at the centre of the induction heater. 10. A furnace as claimed in any one of claims 7 to 9 wherein at least a portion of at least one baffle operatively extends above the molten metal level in the furnace. 11. A furnace as claimed in any one of claims 7 to 10 wherein at least one of the baffles has a cooling conduit there through. 12. A furnace as claimed in any one of claims 1 or 2 in which the throat comprises at least two molten metal transport channels, the first channel communicating with a first portion of the molten bath above the induction heater, and the second channel communicating with a second portion of the molten bath remote from the first portion of the molten bath. 13. A furnace as claimed in claim 12 in which the throat comprises at least three molten metal transport channels, the third channel communicating with a portion of the molten bath remote from the first portion of the molten bath, and the first portion of the molten bath is located between the second and third portions of the molten bath. 14. A furnace as claimed in claim 12 or 13 in which the operatively upper end of the first channel includes a manifold, and the manifold is connected with a plurality of manifold passages, the passages communicating with the operatively upper region of the first portion of the molten bath. 15. A furnace as claimed in claim 14 in which the passages extend through a raised portion of the furnace floor. 16. A furnace as claimed in any one of claims 12 to 15 in which the first channel operatively channels molten metal from the induction heater to the molten bath, and the second channel operatively transports molten metal from the molten bath to the induction heater. 17. A furnace as claimed in any one of claims 13 to 15 in which the first channel operatively channels molten metal from the induction heater to the molten bath, and the second and third channels operatively transports molten metal from the molten bath to the induction heater. 18. A furnace as claimed in any one of claims 13 to 15 in which the first channel operatively channels molten metal from the molten bath to the induction heater, and the second and third channels operatively transport molten metal from the induction heater to the molten metal bath. 19. A furnace as claimed in claim 12 in which the operatively upper end of the second channel includes a manifold, and the manifold is connected with a plurality of manifold passages, the passages communicating with the operatively upper region of the second portion of the molten bath. 20. A furnace as claimed in claim 13 in which the operatively upper end of the second channel includes a manifold and the operatively upper end of the third channel includes a manifold, the second and third channel manifolds are connected with a plurality of manifold passages, the second channel passages communicating with the operatively upper region of the second portion of the molten bath and the third channel passages communicating with the operatively upper region of the third portion of the molten bath. 21. A furnace as claimed in claim 19 in which the first channel operatively channels molten metal from the molten bath to the induction heater, and the second channel operatively transport molten metal from the induction heater to the molten metal bath. 22. A furnace as claimed in claim 20 in which the first channel operatively channels molten metal from molten bath to the induction heater, and the second and third channels operatively transport molten metal from the induction heater to the molten metal bath. 23. A furnace as claimed in any one of claims 19 to 22 in which the passages extend through a raised portion of the furnace floor. 24. A furnace as claimed in any one of claims 16 to 23 wherein the throat includes cooling means for the molten metal channels.